Radiolites squamosus d'Orbigny, 1842

Săsăran, Liana, Săsăran, Emanoil & Bucur, Ioan I., 2018, Upper Cretaceous Rudist-Bearing Mixed Siliciclastic-Carbonate And - Volcanoclastic Deposits From Strâmturii Valley, Borod Basin, Northern Apuseni Mountains: Description, Microfacies And Depositional Environments, Acta Palaeontologica Romaniae 14 (1), pp. 3-20 : 12

Radiolites squamosus d'Orbigny, 1842

Fig. 7 , f-g.

1842 Radiolites squamosa - d'Orbigny, pp. 185-186 1850 Radiolites squamosus d'Orbigny- d'Orbigny, p. 219, pl.561

1908 Radiolites squamosus d'Orbigny- Toucas, p. 71, pl.13, figs.9-11

1976 Radiolites squamosus d'Orbigny- Lupu, p. 124, pl.13, fig.5

1993 Radiolites squamosus d'Orbigny- Swinburne and Noacco, text-fig.2

Material: 1 specimen, both valves (no. 24082 BBU-MPS) .

Description: Small size shell, with right valve (RV) long conical, 40 mm long and 20 mm in diameter at the commissural plane ( Fig. 7 f-g). The ornamentation consists of dense growth lamellae ( Fig. 7f ). The radial bands are folds curved towards the commissure separated by a narrow interband with one fold ( Fig. 7g ). Left valve (LV) is highly convex, with central apex but much eroded ( Fig. 7f ).

Discussion and remarks: Because we found only one specimen, the shell of Radiolites squamosus was not been cut for study in cross-section. This species is also mentioned by Lupu (1976) from RoȘia Basin (Northen Apuseni Mountains).

Age and distribution: early - middle Santonian in France ( Toucas, 1907); late Santonian- early Campanian in Croatia ( Polšak and Mamuzic, 1969), Romania ( Lupu, 1976), Slovenia ( Pleničar and Jurkovsek, 1999), middle-late Campanian in Spain ( Floquet, 1991) and early Maastricthian in east Serbia ( Milovanovic, 1935).

Figures

Fig. 7 a, b Bournonia excavata d'Orbigny, 1847, (inventory no. 24078 BBU-MPS =no.1246 sample field); a transverse section through RV close to the commissure, showing the myocardinal elements: anterior and posterior tooth and myophores (am, pm) of the opposite valve; b view of flat posteroventral side of RV; c Gorjanovicia endrissi (Böhm)(24079 BBU-MPS) – transverse section of RV showing compact layer, concave ventral band (Vb); Ib- narrow and wide Pb with 3 fine rounded costae; d, e Praeradiolites subtoucasi (Toucas): d transverse section through RV (24080-BBU-MPS), unknown commissure. The outer shell layer from ventral side is eroded thus the radial bands are missing. e transverse section on other specimen (24081-BBU- MPS) having outer shell layer partially broken but preserve the myocardinal apparatus. f, g Radiolites squamosus (d'Orbigny): f specimen with both valves showing convex LV, very eroded and the ornamentations of RV consist in dense growth lamellae (sample no. 24082 BBU-MPS); g ventral side of RV of the same specimen showing radial bands (Vb and Pb) with folds upward to commissure and the narrow interband (Ib). h-i Radiolites nouleti (Bayle)(sample no. 24083 BBU-MPS): h large conical RV, thick-shelled, with dense folded growth lamellae, slightly ondulated in large interband (Ib); i transverse section in RVof the same specimen, showing thick cellular outer shell layer, ligamental ridge and accessory cavities. j, k Sphaerulites boreaui (Toucas)(sample no. 24084 BBU-MPS), j specimen with both valves, top view, showing LV, thin and smaller than lower valve and large RV with expanded, sub-horizontal growth lamellae; k transverse section through RV, showing thickness of cellular